RHSA-2011:0534 - Security Advisory

Topic

Updated qemu-kvm packages that fix two security issues, several bugs, and
add various enhancements are now available for Red Hat Enterprise Linux 6.

The Red Hat Security Response Team has rated this update as having
important security impact. Common Vulnerability Scoring System (CVSS) base
scores, which give detailed severity ratings, are available for each
vulnerability from the CVE links in the References section.

Description

KVM (Kernel-based Virtual Machine) is a full virtualization solution for
Linux on AMD64 and Intel 64 systems. qemu-kvm is the user-space component
for running virtual machines using KVM.

It was found that the virtio-blk driver in qemu-kvm did not properly
validate read and write requests from guests. A privileged guest user could
use this flaw to crash the guest or, possibly, execute arbitrary code on
the host. (CVE-2011-1750)

It was found that the PIIX4 Power Management emulation layer in qemu-kvm
did not properly check for hot plug eligibility during device removals. A
privileged guest user could use this flaw to crash the guest or, possibly,
execute arbitrary code on the host. (CVE-2011-1751)

Red Hat would like to thank Nelson Elhage for reporting CVE-2011-1751.

This update also fixes several bugs and adds various enhancements.
Documentation for these bug fixes and enhancements will be available
shortly from the Technical Notes document, linked to in the References
section.

All users of qemu-kvm should upgrade to these updated packages, which
contain backported patches to resolve these issues, and fix the bugs and
add the enhancements noted in the Technical Notes. After installing this
update, shut down all running virtual machines. Once all virtual machines
have shut down, start them again for this update to take effect.

Solution

Before applying this update, make sure all previously-released errata
relevant to your system have been applied.

This update is available via the Red Hat Network. Details on how to
use the Red Hat Network to apply this update are available at
https://access.redhat.com/kb/docs/DOC-11259

Affected Products

• Red Hat Enterprise Linux Server 6 x86_64
• Red Hat Enterprise Linux Workstation 6 x86_64
• Red Hat Enterprise Linux Desktop 6 x86_64
• Red Hat Enterprise Linux for Scientific Computing 6 x86_64
• Red Hat Enterprise Linux Server from RHUI 6 x86_64
• Red Hat Enterprise Linux Server - Extended Life Cycle Support 6 x86_64
• Red Hat Enterprise Linux Server - Extended Life Cycle Support Extension 6 x86_64

Fixes

• BZ - 482427 - support high resolutions
• BZ - 581750 - Vhost: Segfault when assigning a none vhostfd
• BZ - 596610 - "Guest moved used index from 0 to 61440" if remove virtio serial device before virtserialport
• BZ - 599307 - info snapshot return "bdrv_snapshot_list: error -95"
• BZ - 602205 - Could not ping guest successfully after changing e1000 MTU
• BZ - 603413 - RHEL3.9 guest netdump hung with e1000
• BZ - 604992 - index is empty in qemu-doc.html
• BZ - 607598 - Incorrect & misleading error reporting when failing to open a drive due to block driver whitelist denial
• BZ - 608548 - QEMU doesn't respect hardware sector size of underlying block device when doing O_DIRECT
• BZ - 609016 - incorrect committed memory on idle host
• BZ - 613893 - [RFE] qemu-io enable truncate function for qcow2.
• BZ - 615947 - RFE QMP: support of query spice for guest
• BZ - 616187 - vmware device emulation enabled but not supported
• BZ - 616659 - mrg buffers: migration breaks between systems with/without vhost
• BZ - 616703 - qemu-kvm core dump with virtio-serial-pci max-port greater than 31
• BZ - 617119 - Qemu becomes unresponsive during unattended_installation
• BZ - 619168 - qemu should more clearly indicate internal detection of this host out-of-memory condition at startup..
• BZ - 619259 - qemu "-cpu [check | enforce ]" should work even when a model name is not specified on the command line
• BZ - 623552 - SCP image fails from host to guest with vhost on when do migration
• BZ - 623735 - hot unplug of vhost net virtio NIC causes qemu segfault
• BZ - 624396 - migration failed after hot-unplug virtserialport - Unknown savevm section or instance '0000:00:07.0/virtio-console' 0
• BZ - 624572 - time drift after guest running for more than 12 hours
• BZ - 624607 - [qemu] [rhel6] guest installation stop (pause) on 'eother' event over COW disks (thin-provisioning)
• BZ - 624721 - [qemu] [rhel6] bad error handling when qemu has no 'read' permissions over {kernel,initrd} files [pass boot options]
• BZ - 624767 - Replace virtio-net TX timer mitigation with bottom half handler
• BZ - 624790 - pass through fails with KVM using Neterion Inc's X3100 Series 10GbE PCIe I/O Virtualized Server Adapter in Multifunction mode.
• BZ - 625319 - Failed to update the media in floppy device
• BZ - 625333 - qemu treatment of -nodefconfig and -readconfig problematic for debug
• BZ - 625681 - RFE QMP: should have command to disconnect and connect network card for whql testing
• BZ - 625948 - qemu exits when hot adding rtl8139 nic to win2k8 guest
• BZ - 628634 - vhost_net: untested error handling in vhost_net_start
• BZ - 631522 - spice: prepare qxl for 6.1 update.
• BZ - 632257 - Duplicate CPU fea.tures in cpu-x86_64.conf
• BZ - 632458 - Guest may core dump when booting with spice and qxl.
• BZ - 632722 - [6.1 FEAT] QEMU static tracing framework
• BZ - 633394 - [6.1 FEAT] virtio-blk ioeventfd support
• BZ - 633699 - Cannot hot-plug nic in windows VM when the vmem is larger
• BZ - 634153 - coredumped when enable qxl without spice
• BZ - 635354 - Can not commit copy-on-write image's data to raw backing-image
• BZ - 635418 - Allow enable/disable ksm per VM
• BZ - 635527 - KVM:qemu-img re-base poor performance(on local storage) when snapshot to a new disk
• BZ - 635954 - RFE: Assigned device should block migration
• BZ - 636494 - -cpu check does not correctly enforce CPUID items
• BZ - 637180 - watchdog timer isn't reset when qemu resets
• BZ - 637976 - ksmtuned: give a nicer message if retune is called while ksmtuned is off
• BZ - 638468 - [qemu-kvm] bochs vga lfb @ 0xe0000000 causes trouble for hot-plug
• BZ - 639437 - Incorrect russian vnc keymap
• BZ - 641127 - qemu-img ignores close() errors
• BZ - 642131 - qemu-kvm aborts of 'qemu_spice_display_create_update: unhandled depth: 0 bits'
• BZ - 643681 - Do not advertise boot=on capability to libvirt
• BZ - 643687 - Allow to specify boot order on qemu command line.
• BZ - 643970 - guest migration turns failed by the end (16G + stress load)
• BZ - 645342 - Implement QEMU driver for modern sound device like Intel HDA
• BZ - 647307 - Support slow mapping of PCI Bars
• BZ - 647308 - Support Westmere as a CPU model or included within existing models..
• BZ - 647447 - QMP: provide a hmp_passthrough command to allow execution of non-converted commands
• BZ - 647865 - support 2560x1440 in qxl
• BZ - 648333 - TCP checksum overflows in qemu's e1000 emulation code when TSO is enabled in guest OS
• BZ - 653582 - Changing media with -snapshot deletes image file
• BZ - 653972 - qcow2: Backport performance related patches
• BZ - 655735 - qemu-kvm (or libvirt?) permission denied errors when exporting readonly IDE disk to guest
• BZ - 656198 - Can only see 16 virtio ports while assigned 30 virtio serial ports on commandLine
• BZ - 658288 - Include (disabled by default) -fake-machine patch on qemu-kvm RPM spec
• BZ - 662633 - Fix build problem with recent compilers
• BZ - 662701 - Option -enable-kvm should exit when KVM is unavailable
• BZ - 665025 - lost double clicks on slow connections
• BZ - 665299 - load vhost-net by default
• BZ - 667188 - device-assignment leaks option ROM memory
• BZ - 669268 - WinXP hang when reboot after setup copies files to the installation folders
• BZ - 670539 - Block devices don't implement correct flush error handling
• BZ - 670787 - Hot plug the 14st VF to guest causes guest shut down
• BZ - 671100 - possible migration failure due to erroneous interpretation of subsection
• BZ - 672187 - Improper responsive message when shrinking qcow2 image
• BZ - 672191 - spicevmc: flow control on the spice agent channel is missing in both directions
• BZ - 672229 - romfile memory leak
• BZ - 672441 - Tracetool autogenerate qemu-kvm.stp with wrong qemu-kvm path
• BZ - 672720 - getting 'ctrl buffer too small' error on USB passthrough
• BZ - 674539 - slow guests block other guests on the same lan
• BZ - 674562 - disable vhost-net for rhel5 and older guests
• BZ - 675229 - Install of cpu-x86_64.conf bombs for an out of tree build..
• BZ - 676015 - set_link <tap> off not working with vhost-net
• BZ - 676529 - core dumped when save snapshot to non-exist disk
• BZ - 677222 - segment fault happens after hot drive add then drive delete
• BZ - 677712 - disabling vmware device emulation breaks old->new migration
• BZ - 678208 - qemu-kvm hangs when installing guest with -spice option
• BZ - 678524 - Exec based migration randomly fails, particularly under high load
• BZ - 680058 - can't hotplug second vf successful with message "Too many open files"
• BZ - 681777 - floppy I/O error after live migration while floppy in use
• BZ - 683295 - qemu-kvm: Invalid parameter 'vhostforce'
• BZ - 684076 - Segfault occurred during migration
• BZ - 685147 - guest with assigned nic got kernel panic when send system_reset signal in QEMU monitor
• BZ - 688058 - Drive serial number gets truncated
• BZ - 688119 - qcow2: qcow2_open doesn't return useful errors
• BZ - 688146 - qcow2: Some paths fail to handle I/O errors
• BZ - 688147 - qcow2: Reads fail with backing file smaller than snapshot
• BZ - 688428 - qemu-kvm -no-kvm segfaults on pci_add
• BZ - 688572 - spice-server does not switch back to server mouse mode if guest spice-agent dies.
• BZ - 690267 - Backport qemu_get_ram_ptr() performance improvement
• BZ - 693741 - qemu-img re-base fail with read-only new backing file
• BZ - 694095 - Migration fails when migrate guest from RHEL6.1 host to RHEL6 host with the same libvirt version
• BZ - 694196 - RHEL 6.1 qemu-kvm: Specifying ipv6 addresses breaks migration
• BZ - 698906 - CVE-2011-1750 virtio-blk: heap buffer overflow caused by unaligned requests
• BZ - 699773 - CVE-2011-1751 qemu: acpi_piix4: missing hotplug check during device removal

CVEs

• CVE-2011-1750
• CVE-2011-1751

References

• https://access.redhat.com/security/updates/classification/#important
• http://docs.redhat.com/docs/en-US/Red_Hat_Enterprise_Linux/6/html-single/6.1_Technical_Notes/index.html